IIS Reverse Proxy with Docker Librechat

[RealDK69]

I'm running LibreChat in Docker on a Windows 2025 server and have a reverse proxy setup in IIS to forward traffic from librechat.domain.com to LibreChat's Docker instance. This all works fine over http but when I try to access the https URL I receive a "Service Unavailable HTTP Error 503. The service is unavailable." Do I need to configure anything differently in the nginx.conf file or the env in Librechat?

IIS webconfig:

nginx.conf:

server {
listen 80 default_server;
listen [::]:80 default_server;

# To Configure SSL, comment all lines within the Non-SSL section and uncomment all lines under the SSL section. 
########################################  Non-SSL  ########################################
server_name localhost;

# https://docs.nginx.com/nginx/admin-guide/web-server/compression/
# gzip on;
# gzip_vary on;
# gzip_proxied any;
# gzip_comp_level 6;
# gzip_buffers 16 8k;
# gzip_http_version 1.1;
# gzip_types text/css application/javascript application/json application/octet-stream;

# Increase the client_max_body_size to allow larger file uploads
# The default limits for image uploads as of 11/22/23 is 20MB/file, and 25MB/request
client_max_body_size 25M;

location /api/ {
    proxy_pass http://api:3080$request_uri;
}

location / {
    proxy_pass http://api:3080/;
}

########################################  SSL  ########################################

# Redirect all http traffic to https

location / {

return 301 https://$host$request_uri;

}

}

#server {

listen 443 ssl http2;

listen [::]:443 ssl http2;

https://docs.nginx.com/nginx/admin-guide/web-server/compression/

gzip on;

gzip_vary on;

gzip_proxied any;

gzip_comp_level 6;

gzip_buffers 16 8k;

gzip_http_version 1.1;

gzip_types text/css application/javascript application/json application/octet-stream;

ssl_certificate /etc/nginx/ssl/nginx.crt;

ssl_certificate_key /etc/nginx/ssl/nginx.key;

ssl_session_timeout 1d;

ssl_session_cache shared:MozSSL:10m; # about 40000 sessions

ssl_session_tickets off;

# curl https://ssl-config.mozilla.org/ffdhe2048.txt > /etc/nginx/ssl/dhparam

ssl_dhparam /etc/nginx/ssl/dhparam;

# intermediate configuration

ssl_protocols TLSv1.2 TLSv1.3;

ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-CHACHA20-POLY1305;

ssl_prefer_server_ciphers off;

# HSTS (ngx_http_headers_module is required) (63072000 seconds)

add_header Strict-Transport-Security "max-age=63072000" always;

# OCSP stapling

ssl_stapling on;

ssl_stapling_verify on;

# verify chain of trust of OCSP response using Root CA and Intermediate certs

ssl_trusted_certificate /etc/nginx/ssl/ca.crt;

# replace with the IP address of your resolver

resolver 127.0.0.1;

server_name localhost;

# Increase the client_max_body_size to allow larger file uploads

# The default limits for image uploads as of 11/22/23 is 20MB/file, and 25MB/request

client_max_body_size 25M;

location /api {

proxy_pass http://api:3080/api;

}

location / {

proxy_pass http://api:3080;

}

#}

This is all being configured in a corporate environment. Strange that http works but not https.